U.S. stocks cut their morning losses and finished higher Monday, rebounding from one of their worst weeks of the year. But the gains were slim as investors gear up for first quarter earnings reports.

Kick-off to earnings: Investors will be shifting gears this week to first-quarter earnings. Aluminum producer Alcoa(AA) unofficially kicked things off with its quarterly report after the closing bell. The Dow component posted earnings that topped forecasts. But sales were below estimates. JPMorgan Chase(JPM) and Wells Fargo are on tap for Friday. They are the first two of the big banks to report.

Overall, analysts are forecasting first-quarter earnings to be up just 1.5% compared with a year earlier, according to Thomson Reuters.

The results over the next few weeks "will likely determine whether investors take profits on a huge Q1 stock market rally, or continue to pile on long positions to prepare for a potential continued run higher," said analysts at Lido Isle Advisors.

Rally hits speed bump: Stocks have lost steam in the last few weeks, on renewed worries about Europe, softer U.S. economic data, particularly the March jobs report, and concerns about the nuclear threat from North Korea.

But following this year's huge rally and new record highs for the Dow and S&P 500, experts say a pause is normal.

Any pullback could also be the start of a short-term correction "that will wring out some of the excesses that have crept into the market, most notably overly optimistic sentiment," said William Riegel, head of equity investments at TIAA-CREF.

What's moving:General Electric(GE) said it planned to buy energy company Lufkin Industries(LUFK) for $3.3 billion. Shares of Lufkin, which builds and maintains equipment for oil and gas wells, surged nearly 38%.

Anheuser-Busch InBev's(BUD) proposed $20 billion acquisition of Mexican brewer Grupo Modelo appears to be back on track after the companies, along with Constellation Brands(STZ) and Crown Imports, said they'd reached an agreement that would settle the Justice Department's objections to the deal.

Global pressures:Portugal plans to cut spending on education, health and welfare in a bid to meet the terms of an international rescue after the country's constitutional court shot holes in its austerity program. Despite a sell-off in Portuguese stocks, the main European markets ended slightly higher.